4-chloroindole-3-acetic acid and plant growth

4-Chloroindole-3-acetic acid (4-Cl-IAA) is a potent auxin in various auxin bioassays. Researchers have used 4-Cl-IAA as well as other halogenated auxi ns in biological assays to understand the structural features of auxins req uired to induce auxin mediated growth in plants. 4-Cl-IAA is a naturally oc curring auxin in plants from the Vicieae tribe of the Fabaceae family; and 4-Cl-IAA has also been identified in one species outside the Vicieae tribe, Pinus sylvestris. The apparent function of the unique auxin 4-Cl-IAA in no rmal plant growth and development will be discussed with a focus on Pisum s ativum and Vicia faba.